Organic light-emitting diode (OLED) display panels are welcome to the people because of the features of slim size, low power consumption, wide viewing angle, wide color gamut, high contrast, and etc. OLED display panels can be sorted as passive matrix OLED (PMOLED) display panels and active matrix OLED (AMOLED) display panels. The common AMOLED display panel includes a display area and a boundary area, and the boundary area surrounds the display area. The display area includes a plurality of anodes, a plurality of organic light-emitting layers, and a cathode covering the whole surface. These anodes and organic light-emitting layers are arranged in an array. Therefore, some anodes at the specific columns/lines are close to the center of the display area, and some are close to the boundary area (e.g. the anodes located at the boundary of the display area). During the process for forming the anodes, i.e. the development and etching processes, as the anodes at the center of the display area are properly formed under the etching treatment, some additional material of the anodes at the boundary of the display area would be etched due to the lack of anodes outside the anodes at the boundary of the display area, such that the size of the anodes at the boundary of the display area would be smaller than that at the center of the display area. To be more specific, that is, the length and the width would be different. Thus, even under the same design conditions, the actual size of the anodes would be different, e.g. different densities of anodes, which may cause a non-uniform image quality of the AMOLED display panel.